London base jumpers who went to the extreme for a view of Olympic Park

Staying one jump ahead: one of the base jumpers descends into Stratford High Street before running away

Two daring base jumpers stunned onlookers today as they dropped into east London just before dawn.

The parachutists are believed to have jumped from a crane close to the Olympic Park in Stratford just after 5am.

However, mystery surrounds the identity of the jumpers who folded up their parachutes within seconds of landing before running away into neighbouring streets.

The men are believed to have broken into a residential development to climb the crane in Stratford High Street before jumping into the road below.

Witnesses said the two jumped within a minute of each other and landed unscathed. Amateur photographer Dan McCurry, who saw the jump, said: "While taking photos of the sunrise from Bow flyover, facing towards Stratford, a parachute appeared in the frame."

He added: "I got a second shot as he came down to land in Stratford High Street, then another shot moments after he landed on the east pavement and his chute deflated.

"About a minute later a second descended. They appear to have come from the tall crane on the western side of the road, which is the Olympic site. The crane is part of a large residential block opposite the Greenway." The Olympic Delivery Authority said the crane was not on the Olympic site and said it posed no security risk to the 2012 Games development.

Base jumping was made popular in 1978 by film-maker Carl Boenish, who filmed jumps from El Capitan cliff face in Yosemite National park and coined the term for the extreme sport - which killed him six years later.

The term "base" is an acronym for the four categories of objects from which the parachutists jump: building, antenna, span and earth.